blob: 9f350e05ef68a1dfc76e333f328ca7f66ed3a4cc [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
/*
* Pvpanic Device Support
*
* Copyright (C) 2013 Fujitsu.
* Copyright (C) 2018 ZTE.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/kexec.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/types.h>
#include <uapi/misc/pvpanic.h>
static void __iomem *base;
static unsigned int capability = PVPANIC_PANICKED | PVPANIC_CRASH_LOADED;
static unsigned int events;
static ssize_t capability_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sysfs_emit(buf, "%x\n", capability);
}
static DEVICE_ATTR_RO(capability);
static ssize_t events_show(struct device *dev, struct device_attribute *attr, char *buf)
{
return sysfs_emit(buf, "%x\n", events);
}
static ssize_t events_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
unsigned int tmp;
int err;
err = kstrtouint(buf, 16, &tmp);
if (err)
return err;
if ((tmp & capability) != tmp)
return -EINVAL;
events = tmp;
return count;
}
static DEVICE_ATTR_RW(events);
static struct attribute *pvpanic_dev_attrs[] = {
&dev_attr_capability.attr,
&dev_attr_events.attr,
NULL
};
ATTRIBUTE_GROUPS(pvpanic_dev);
MODULE_AUTHOR("Hu Tao <hutao@cn.fujitsu.com>");
MODULE_DESCRIPTION("pvpanic device driver");
MODULE_LICENSE("GPL");
static void
pvpanic_send_event(unsigned int event)
{
if (event & capability & events)
iowrite8(event, base);
}
static int
pvpanic_panic_notify(struct notifier_block *nb, unsigned long code,
void *unused)
{
unsigned int event = PVPANIC_PANICKED;
if (kexec_crash_loaded())
event = PVPANIC_CRASH_LOADED;
pvpanic_send_event(event);
return NOTIFY_DONE;
}
static struct notifier_block pvpanic_panic_nb = {
.notifier_call = pvpanic_panic_notify,
.priority = 1, /* let this called before broken drm_fb_helper */
};
static int pvpanic_mmio_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct resource *res;
res = platform_get_mem_or_io(pdev, 0);
if (!res)
return -EINVAL;
switch (resource_type(res)) {
case IORESOURCE_IO:
base = devm_ioport_map(dev, res->start, resource_size(res));
if (!base)
return -ENOMEM;
break;
case IORESOURCE_MEM:
base = devm_ioremap_resource(dev, res);
if (IS_ERR(base))
return PTR_ERR(base);
break;
default:
return -EINVAL;
}
/* initlize capability by RDPT */
capability &= ioread8(base);
events = capability;
if (capability)
atomic_notifier_chain_register(&panic_notifier_list,
&pvpanic_panic_nb);
return 0;
}
static int pvpanic_mmio_remove(struct platform_device *pdev)
{
if (capability)
atomic_notifier_chain_unregister(&panic_notifier_list,
&pvpanic_panic_nb);
return 0;
}
static const struct of_device_id pvpanic_mmio_match[] = {
{ .compatible = "qemu,pvpanic-mmio", },
{}
};
static const struct acpi_device_id pvpanic_device_ids[] = {
{ "QEMU0001", 0 },
{ "", 0 }
};
MODULE_DEVICE_TABLE(acpi, pvpanic_device_ids);
static struct platform_driver pvpanic_mmio_driver = {
.driver = {
.name = "pvpanic-mmio",
.of_match_table = pvpanic_mmio_match,
.acpi_match_table = pvpanic_device_ids,
.dev_groups = pvpanic_dev_groups,
},
.probe = pvpanic_mmio_probe,
.remove = pvpanic_mmio_remove,
};
module_platform_driver(pvpanic_mmio_driver);